1. Field of the Invention
The invention relates to an elastomeric strip, preferably of the channel-shaped type, for sealing and/or decorative purposes, such as, for example, gripping and covering edge flanges on the periphery of a vehicle door, a door opening or the like. More particularly, the invention relates to an improved elastomeric strip and method of manufacture in which the strip is provided with longitudinally-spaced degraded regions, corresponding to the longitudinally-spaced curved sections of the flange, whereby the degraded regions of the elastomeric strip can faithfully follow the curved sections of the flange when the strip is mounted thereon.
2. Description of the Prior Art
U.S. Pat. No. 4,343,845 which issued to Burden et al on Aug. 10, 1982, discloses (see FIG. 1A) an elastomeric strip 1 and method of manufacturing the same, in which the elastomeric strip 1 had a selected lateral region 2 along the length thereof reinforced with degradable material 4 and at least one other lateral region 3 reinforced with material that is non-degradable. Accordingly, when the weatherstrip is subjected to degredation conditions, the degradable material 4 in the selected region 2 is degraded and the non-degradable material 5 is in the other region 3 is not degraded. The degraded material breaks when the strip is flexed, so that longitudinal displacement of the selected region of the frame portion is no longer inhibited, resulting in an elastomeric strip of improved flexibility. The longitudinal displacement of the other region 3 is maintained for preventing undue elongation or stretching of the strip. More specifically, selected laterally spaced apart regions 2, 3 of the displaceable frame portions of the strip, such as the central and/or outer regions or portions thereof are reinforced with a degradable and a non-degradable material respectively. Subsequently, the entire weather strip is subjected to a degrading environment and only the degradable material is selectively degraded resulting in increased flexibility of the strip, allowing it to faithfully accommodate inside, outside, and lateral curves, or combinations thereof. Also, limited elongation of the strip is achieved due to the presence of non-degraded material.
Japanese Patent Application No. 75627/78, shows a channel-shaped elastomeric strip having a ladder-like frame having a plurality of parallel, spaced-apart metal rungs joined together by thin webs. A strip degrading apparatus comprising a power source is disclosed having prongs insertable through the strip coating and into contact with a pair of adjacent metal rungs for applying electrical current thereto. This causes the thin web between the two metal rungs to melt, allowing elongation of the strip to occur in this region.
Problems occur in attempting to utilize the teachings of these patents in connection with the assembly of an automobile or the like, in which an elastomeric strip of finite length is mounted on a flange surrounding a door or a door opening, for example. One problem is that it is necessary for the automobile manufacturer receiving the elastomeric strip to degrade the sections of the strip conforming to the curved sections of the flange. This operation is time consuming, thereby adversely affecting the efficiency of the manufacturing operation. Additionally, the operation requires apparatus on hand to handle the strips and perform the breaking or degrading operation, threby adversely affecting plant space considerations.
Another problem is presented by the prior art in relation to achieving degredation of longitudinally-spaced regions of the elastomeric strip. To achieve such degredation, it is necessary for the prongs of the strip degrading apparatus to pierce the elastomeric coating of the strip and to contact longitudinally-spaced wires or rungs of the strip support frame. Since the wires and rings are covered by the coating, it is difficult to accurately position the strip degrading apparatus so that the prongs accurately engage them, resulting in a hit-and-run operation. With the wire support frame, such prong and wire engagement is virtually impossible.